Organic electronic devices such as organic photovoltaic devices or organic light emitting devices (OLED) are comprised of several functional layers in which the hole-transport and electron-transport layers are often p-doped and n-doped, respectively, to improve the charge injection properties from the electrodes and to lower resistivity losses for an overall enhanced device performance. These organic electronic devices have a large variety of different organic layer structures. As an example, white light emitting OLEDs may have a light emitting layer with multiple different light-emitting molecules to generate white light emission from this single layer, a stack of multiple light-emitting layers each emitting a different color of light or light emitting units each comprising at least one light-emitting layer sandwiched between additional functional layers, where two or more of these units are arranged on top of each other (stacked units) in order to emit white light as a stacked OLED. Doped organic layers are also frequently used in stacked OLEDs to form a serial connection between multiple emitting units providing the technology to realize efficient white OLEDs at high brightness levels and long lifetimes.
US 2010/0288362 A1 discloses an organic electronic device with improved performance, which could be used as a solar cell or as a stacked organic light emitting device.
To provide OLEDs delivering stable performance over time the doping conditions (doping concentration) in the organic layers must be stable over time to guarantee best performance even after several hundreds of operating hours. Since the operation of organic electronic devices caused elevated temperatures of up to 100° C. during operation and for special applications operation at elevated temperatures even slightly above 100° C. is required, the organic layers and its composition must be stable at elevated temperatures. Furthermore the organic layers must be stable when exposed to light, especially UV light. There is a demand for providing such an organic electronic device showing an excellent performance, which is as stable as possible over time.